Hi all

Does anyone know where I can find a charge lead that allows me to directly charge a NiMH or Lipo battery that plugs into a JR9303 or DSX9 transmitter. I’ve searched everywhere but can’t find a lead that will attach to plug into standard banana plugs. Anyone know what the white connector to JR TX is actually called?

I do not know what the connector is called but, a work around is remove the shield on a female servo extension. That leaves you 3 pins the center is positive and the black wire side is negative. These pins will plug into the white connector. Put banana plugs on the other end and you gave a charge lead. You must follow polarity manually. I usually remove the signal pin

NiMH or Lipo battery that plugs into a JR9303 or DSX9 transmitter

That’s not very specific.

I'm just saying as an owner of a 9303, I know it only shipped with a NIMH battery. If you wanted to put a lipo in it, it was aftermarket. And, every aftermarket lipo I've ever used has balance leads, hence my statement. I'm not sure what point you're trying to make.

Not sure he knows what the point is either......maybe he's trying to increase his post count ???

Been there, done that and old enough to know better.....

Well that took a turn! Anyway I have an aftermarket 3cell Life with a balance lead so I balance charge it outside the TX every time I charge. The frustrating thing was finding a bloody charge lead for it (not balance lead). Have modified a female jr Servo extension lead as suggested and it works great

Dunno what to tell you. Mines right here.

if it ain't broke, break it.

JR9303 Radio.

I have no idea why you are using a 3s lipo battery in the JR9303 radio. It was designed for NiMH batteries 8cells at 1.2volts = 9.6 volts. Fully charged it would be 8x1.4v/cell= 11.2volts.

The lipo is 11.1volts discharged(3.7v/cell) or 12.6 volts at a full charge (4.2v/cell). I guess you are getting away with this, but this radio was not designed for a lipo battery. I would like to see the label and connector wiring.

Voltage has been reduced with a resistor.

if it ain't broke, break it.

Calling BS - Don't do what he is suggesting. Use the Proper Battery and voltage.

A resistor will consume energy, but that's not the main reason not to use one. The voltage drop across the resistor will vary with the current, so if your load isn't constant (it never is) the voltage will vary. That's not what you want from a regulator. Never use a series resistor as a voltage regulator!

There are two big categories of voltage regulator: linear and switcher.

A linear regulator usually comes as a three-legger: an input pin, ground and an output pin. Typical example: LM7805. They have good regulation and are easy to use. Main drawback: they're not efficient. The load current passes through the regulator, and causes a voltage drop there, like the series resistor would. If your 5V circuit draws 1A you'll draw that 1A from the 9V, so the load's 5W will require 9W from your power supply, that's an efficiency of 55%. This becomes even worse if your input voltage is higher, like 24V. With an input voltage this high the regulator needs considerable cooling. You don't want a linear regulator for this kind of application.

A switcher (or SMPS, for Switched-Mode Power Supply) is the solution. This uses a coil to build up a magnetic field, which in turn is converted back into the output voltage. Switchers are a bit more complicated in operation than linear regulators, but they're much more efficient; efficiencies of 95% are often possible. Since they work at higher frequencies (100s of kHz to several MHz) board layout is premium to reduce radiation. Proper component selection and careful PCB layout are also important to get high efficiency.

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